Applications:

Bulk, thin polycrystalline films on silicon or other substrate materials

Problem:

Conversion efficiency of photons to carriers due to short optical path length in the crystalline silicon cells

Technology:

The photonic crystal backside reflector described herein reduces problems with light trapping in thin crystalline silicon solar cells. The novel solar cell consists of a photoactive region, a Lambertian surface on the top side of the photoactive region, and a photonic crystal on the backside of the photoactive region. The backside reflector is in the form of a super prism structure, and allows for large angle reflection of light due to anomalous dispersion created by the photonic crystals. Processing of the super prism structure is based on plasma etching for via-hole fabrication and annealing.